The empty gun - The IPCC's recently issued Climate Change 2007 Summary for Policymakers (SPM) puts me in mind of a bank robber demanding money while waving an unloaded pistol. It is difficult at best to evaluate the statements made in the summary without being able to review the scientific underpinnings to be rendered in later installments of this year's Fourth Assessment Report. It appears, at least to your humble scribe, that this was deliberate. Indeed, the IPCC, along with their counterparts in the establishment media and elsewhere, seem to want international policymakers to react to this report as if everything contained therein was indisputable fact.

Unfortunately, much of what is contained in the SPM is indeed either unsupported by current science or contradicted by points made in the SPM itself. (At the outset, I will credit the IPCC for pointing out some of the shortcomings in their data.) For starters, the report proposes that "[t]he annual CO2 concentration growth-rate was larger during the last 10 years...than it has been since the beginning of continuous direct atmospheric measurements." Now I'm nobody's math major, but I would contend that any 10 year stretch would have a 50 percent chance of having a higher than average CO2 concentration growth-rate than that seen over a longer time-scale; to conclude that this is evidence of longer-term climate change is difficult at best. To it's credit, the SPM does concede that "there is year-to-year variability in growth rates."

The SPM notes that "[t]he average atmospheric water vapor content has increased since at least the 1980s over land and ocean." But because the IPCC does not provide the scientific research supporting this statement, we are not able to conclude whether increased water vapor is a dependent or independent variable as it regards observed changes in global temperature. As noted elsewhere, there is a growing body of research that posits that water vapor is in fact the independent variable, with CO2 being the dependent variable in the climate change equation. (For that matter, it may not be clear whether rising CO2 levels are the cause of climate change or are themselves caused by a warming atmosphere.)

The IPCC does (sort of) confess its ignorance of several factors that may yet mitigate the effects of CO2 in the atmosphere. In its listing of "Relative Forcing Components" the SPM speaks to the IPCC's relative ignorance of the impacts of land use, total airborne aerosols or variances in solar irradiance on climate. Indeed, the report states that "[a]dditional forcing factors not included here are considered to have a very low level of scientific understanding." And while the report states that "Arctic temperatures increased at almost twice the global average rate in the past 100 years," it also acknowledges that Arctic temperatures vary widely over time and that "a warm period also observed from 1925 to 1945" (during which, there was a 10 year period of constant or declining CO2 concentrations.)

The report also directly contradicts itself by hinting at "suggestions of increased intense tropical cyclone activity" related to global warming, while (on the same page, no less) it admits that there is "insufficient evidence to determine whether trends exist in...small scale phenomena such as tornadoes." But the fatal flaw of this report is that, like much of the hysteria surrounding climate change, it depends heavily on models that cannot take into account forcing factors where there is a "very low level of scientific understanding." While the current models are seemingly adequate to predict climate behavior over oceans and continents, the SPM directly concedes that "[d]ifficulties remain in reliably simulating and attributing observed temperature changes at smaller scales. On these scales, climate variability is relatively larger making it harder to distinguish changes expected due to external forcings."

Other factors that detract from the value of the IPCC's models include the impact of clouds; the SPM itself states clearly that small-scale "[c]loud feedbacks remain the largest source of uncertainty." As much was elucidated by University of London Professor Philip Stott in a February 3, 2007 Wall Street Journal opinion piece. (Subscription required.)

For the skeptic, however, the problem remains, as ever, water vapor and clouds. Enormous uncertainties persist with respect to the role of clouds in climate change. Moreover, models that strive to incorporate everything, from aerosols to vegetation and volcanoes to ocean currents, may look convincing, but the error range associated with each additional factor results in near-total uncertainty. Yet, there is a greater concern. Throughout the history of science, monocausal explanations that overemphasize the dominance of one factor in immensely complex processes (in this case, the human-induced emissions of greenhouse gases) have been inevitably replaced by more powerful theories.

Sadly, like much of the IPCC's previous work product, this SPM is another attempt on the part of the global warming establishment to (over)emphasize the risks of inaction against climate change - this being the original sin of global warming evangelists - while negating the real risks of action, of which there are at least two. The financial risk is that we will spend too much of the global economic product in order to implement CO2-abating technologies that are presently inadequate or inefficient. The more significant risk however is that of inevitably sacrificing lives that could be saved today, were it not for the application of scarce dollars to potentially saving lives in the indeterminate future. That the IPCC refuses to speak clearly to this moral risk - the risk that many of today's generation will have to die, or live with a diminished quality of life - establishes the ethical bankruptcy of the climate change confederacy.